n=int(input())
if(n>=30):
    print("Yes")
else:
    print('No') n=int(input()) n int(input()) int input() input if(n>=30):
    print("Yes")
else:
    print('No') n>=30 n 30 print("Yes") print "Yes" print('No') print 'No' n=int(input()) int(input()) n
n=int(input())
if(n>=30):
    print("Yes")
else:
    print('No')
